There is the battery back up of 3.5 hours. The dimension of the phone is 94x52x16mm and weighs only 81 grams. The phone has got the walkman player. There is the facility of Shake control in the phone in which you can change the songs by just shaking the phone. You can tune yourself into FM also and can hear your favorite channel.The Sony Ericsson Yendo Deals can be used as a contract phone, pay as you go phone, SIM free mobile phone as well . In contract deals you can pay your bills monthly. By signing the contract period of 12-24 months. In pay as you go phones you can make the payments of your bill in advance. SIM card of your choice as well as the mobile phone is the the deal offered by the SIM free deals. Virgin ,Vodafone,Orange,O2,Three,T-Mobile are the networks you can avail on your mobile phone.